Dr B.L. Chua, 41, first felt numbness in his hands and feet six years ago. Since then, the general practitioner has felt increasing numbness and pain in his limbs.

He suspected that he could have multiple sclerosis (MS) but it was only last year, when he experienced pain in the eye and partial loss of vision, that the diagnosis of MS was confirmed.

During the worst period of his symptoms, Dr Chua had to rely on vision in one eye and had difficulty driving and reading.

The father of three young children, who is married to a dentist, is now on Betaferon medication. He makes regular trips to the neurology departments at the National University Hospital and Tan Tock Seng Hospital where periodic MRI scans are carried out to monitor the condition.

"There is treatment for MS especially when the diagnosis is early. Medication too helps to prevent relapses," he said.

Treatment options include physiotherapy and using drugs to slow down the progress of MS.

Addressing another area of concern, Dr Chua said: "Treatment for MS is expensive and subsidies are non-existent in Singapore.

"I hope that subsidy schemes will be considered to assist sufferers of MS soon."

Dr Ho King Hee, a consultant neurologist and physician at K H Ho Neurology & Medical Clinic in Gleneagles Medical Centre, said that not all MS patients need drug therapies.

He said: "Some patients have a stable form of the disease and will not get much disease progression with time. The difficulty is trying to find out which patients need treatment and which do not.

"Also, some patients have such advanced disease that they will not benefit from treatment."

Dr Chua continues to lead a normal life and has a hectic schedule balancing work and family life. He spends five days a week at his clinic and engages fellow MS patients in conversations on treatment options.

He said: "I do sometimes ask, 'Why me?' but I am fortunate that I can afford the treatment and I have strong family support too."

What is multiple sclerosis?

Most of us take it for granted that we can run, see and talk. But when a disease affects such everyday abilities, it can be very disruptive.

The disease called multiple sclerosis (MS) - in which the immune system attacks the central nervous system - can result in, among other symptoms, fatigue, loss of eyesight and balance and coordination problems.

For people like sportsmen and actors, a disease like MS can badly affect their careers.

For instance, in 2001, Javier Artero Lopez, a Spanish footballer, had to quit at the peak of his career at the age of 33 because of MS.

The late American comedian Richard Pryor was diagnosed with it and spent many years in a wheelchair prior to his death in 2005 at the age of 65.

Another American comedian Jonathan Katz, 62, tried at first to hide his MS but later went public, gaining much support for his courage.

There is no known cure although drugs can inhibit the disease's progression. In Asia, MS is fortunately not common, affecting five in 100,000 people.

Dr Alvin Seah, a consultant neurologist at Raffles Hospital, said that although there has been no formal survey done in Singapore, there are about 80 MS patients here. The disease is twice as common in women as it is in men.

In MS, the immune system attacks the central nervous system, affecting the ability of nerve cells in the brain and spinal cord to communicate with each other.

This degenerative process, or demyelination, occurs when the insulating myelin sheaths around the neuron cells - which conduct electrical signals - are damaged.

"Patients commonly experience sudden loss of vision or even blindness," Dr Seah said.

The disease can attack suddenly or be progressive. The most common is termed "relapsing-remitting".

In this phase, the patient suffers from a series of attacks after which the symptoms decrease and return after a lapse of time.

This relapsing-remitting phase will eventually develop into the secondary progressive phase where patients will suffer from progressive neurological decline and symptoms of the disease will worsen.

The cause of MS is mostly unknown though some scientists believe a genetic defect could be a factor. The environment as a factor is currently being investigated too.

"Multiple sclerosis is least common along the equator and becomes more common at higher latitudes, especially in countries like Canada, Australia, New Zealand and Japan," said Dr Seah.

The drug Tysabri has proven to be effective against MS but it is currently not available in Singapore.

Here, other drugs called beta-interferons are used to slow the progress of the disease.

Other methods such as physiotherapy are also important in the treatment of MS.

Most patients with MS will have a normal lifespan.

"If medically there is not much to offer, good nursing care and a warm supportive family environment can make a lot of difference," said Dr Seah.